In a radio frequency communications system 100, e.g. as illustrated in FIG. 1 transmission may occur via multiple transmission channels, e.g. when using a transmission system including multiple transmit and/or receive antennas or when receiving signals from multiple radio cells 110, 112.
Mobile phones 120 with single transceiver as depicted in FIG. 1 have only limited capacity to receive cell broadcast (CB) messages 102 and at the same time perform idle task measurements, e.g. measurements at frequencies different from current serving cell's 110 frequency such as inter-frequency and inter-RAT (Radio Access Technology) measurements as defined in mobile communications standards like UMTS. This can result in either loss of mobility when the preference is given to CB reception 102 or loss of cell CB messages when the preference is given to idle task measurements 104.
Current mobile standardization such as 3GPP specification, in particular TS 25.331, TS 23.041, and TR 25.925 actually foresees a relaxed scheduling with up to two discontinuous reception (DRX) levels for CB messages to facilitate that parallel work at UE side and also to enable power saving.
But especially for earthquake warning systems, it was observed that operators are using a very frequent scheduling of CB messages. Some operators use for their application of an Early Earthquake Warning system (EEW) the highest possible transmission rate for CB messages, i.e., they use a cell broadcast service (CBS) allocation period of one, which means that the UE is expected to continuously decode received control messages such as Common Traffic Channel (CTCH) transport blocks to receive CB messages.
Other operators use a similar high transmission rate for CB message with a CBS allocation period of six, which means that the UE is expected to decode received control messages such as CTCH transport blocks used to transmit CB messages each sixth frame.
By using such a tight scheduling current UEs are not able to receive all CB messages and perform idle task measurements at the same time. Therefore, there is a need for an improvement of the UE in order to facilitate idle task measurements and CB reception in the same time interval, in particular for a UE using a single transceiver for these two tasks.